Something tells me Nvidia has all this tech to begin with, just let it dribble out for marketing purposes, why do FXAA if TXAA is better and is advertised even better, beats MSAA with no performance hit similar to FXAA...

The above (easy on performance) plus some people actually like the way it looks. Personally I hate it (think it is worse than nothing), but unlike a lot of people, I don't expect everyone else to have the same opinions as myself.